The art is replete with package closures for preventing packages from opening accidentally, for inhibiting or deterring unauthorized persons from opening the package, and for indicating that the packages have been opened, thereby enabling, for example, a consumer or other user to verify whether the closure has been previously opened.
One type of closure in use today is a multilayer security laminate comprising, in order, (1) a verification layer such as a piece of CONFIRM Brand Retroreflective Sheeting (generally available from the Minnesota Mining and Manufacturing Co., of St. Paul, Minn.) adhered to (2) a layer of polyester which is substantially coextensive with the layer of CONFIRM, and (3) a layer of adhesive which bonds the security laminate to the package. If desired, a legend or message may be printed on the upper surface of the polyester so as to be visible through the verification layer.
The layer of adhesive may comprise a pattern of two kinds of adhesive, one of which is selected to preferentially adhere to the polyester and the other of which is selected to preferentially adhere to the substrate. Thus, when opening or removal of such a closure is attempted by prying the polyester from the substrate, the pattern of the adhesive becomes readily apparent, thereby providing indication that the seal has been tampered.
Other examples of prior art packages are shown in U.S. Pat. Nos. 4,709,396 and 4,709,397 to Voshall et al. and U.S. Pat. No. 4,838,708 to Holcomb et al. Many existing prior art security packages encounter problems because they are not reusable. Typically a prior art security package is used once and then disposed, as it cannot thereafter be used to detect whether a package has been tampered with or opened.
Existing prior art security packages typically rely on at least one layer of adhesive. The adhesive may be adversely affected by environmental conditions such as extreme heat, humidity or dust.
U.S. patent application Ser. No. 07/875,186, filed Apr. 28, 1992, now U.S. Pat. No. 5,201,101, issued Apr. 12, 1992, and filed on the same day as the present application describes a method of attaching articles and a pair of articles attached by that method. The entire contents of that patent application are herein expressly incorporated by reference.
U.S. Pat. No. 4,875,259 to Appeldorn discloses several intermeshable articles. Some of the species of intermeshable articles disclosed in 4,875,259 require alignment before pressing the structured surfaces together. The entire contents of U.S. Pat. No. 4,875,259 are herein incorporated by reference.